introduce output filters

iast-czech.c

@@ -101,12 +101,23 @@ static const struct transliteration_letter table[] = {
 	{0, 0, NULL}
 };
 
+static void dummy_filter(struct syllable *chain)
+{
+	printf("%s%s\n", chain->next->data, chain->next->next->data);
+}
+
+static const transliteration_filter_t filters[] = {
+	dummy_filter,
+	NULL
+};
+
 struct transliteration_context *transliteration_context_iast_czech_alloc()
 {
 	struct transliteration_context *context;
 
 	context = malloc(sizeof(*context));
 	context->table = table;
+	context->filters = filters;
 
 	return context;
 }

iast.c

@@ -99,12 +99,17 @@ static const struct transliteration_letter table[] = {
 	{0, 0, NULL}
 };
 
+static const transliteration_filter_t filters[] = {
+	NULL
+};
+
 struct transliteration_context *transliteration_context_iast_alloc()
 {
 	struct transliteration_context *context;
 
 	context = malloc(sizeof(*context));
 	context->table = table;
+	context->filters = filters;
 
 	return context;
 }

transliteration.c

@@ -36,6 +36,17 @@ static void syllable_modify(struct syllable *syllable, const char *data)
 	syllable->data = strdup(buffer);
 }
 
+static void apply_transliteration_filters(struct syllable *head,
+	const transliteration_filter_t *filters)
+{
+	const transliteration_filter_t *filter = filters;
+
+	while (*filter) {
+		(*filter)(head);
+		filter++;
+	}
+}
+
 char *transliterate_devanagari_to_latin(const char *text,
 	struct transliteration_context *context)
 {
@@ -72,6 +83,8 @@ char *transliterate_devanagari_to_latin(const char *text,
 		free(tmp);
 	}
 
+	apply_transliteration_filters(head, context->filters);
+
 	return syllable_chain_to_string(head);
 }
 

transliteration.h

@@ -9,6 +9,8 @@
 #define FLAG_REGULAR	1 << 0
 #define FLAG_MODIFIER	1 << 1
 
+typedef void (*transliteration_filter_t)(struct syllable *syllable_chain);
+
 struct transliteration_letter {
 	unsigned int code;
 	unsigned int flags;
@@ -17,6 +19,7 @@ struct transliteration_letter {
 
 struct transliteration_context {
 	const struct transliteration_letter *table;
+	const transliteration_filter_t *filters;
 };
 
 char *transliterate_devanagari_to_latin(const char *text,